Plotting instrument



3 Sheets-Sheet 1 A. J. KRAMER PLOTTING INSTRUMENT Filed April 2, 1943 June 20, 1944.

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June 20, 1944. J KRAMER PLOTTING INSTRUMENT 3 Sheets-Sheet 2 Filed April 2, 1943 INVENTOR A. J.KRAMER ATTORNEIS June 20,1944, A. J. KRAMER 2,351,769

PLOTTING INSTRUMENT Fil ed April 2, 1943 3 Sheets-Sheet 3 QINVENTOR A.J.KRAMER ATTOBNEYS J ing forwardly thereabove.

Patented June 20, 1944 I PLOTTING INSTRUMENT Albert J. Kramer, Arlington, Va., assignor to Claude R. Wickard, as Secretary of Agriculture of the United States of America, and his successors in oflice Application April 2, 1943, Serial No. 481,560

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3'70 0. G. 757) 4 Claims.

This application is made under the act of March 3, 1883, as amended by the the act of April 30, 1928, and the invention herein described, if pat ented, may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to me of any royalty thereon.

This invention relates to plotting instruments of the same general character as those disclosed in the patent to Wernstedt, No. 2,303,099, granted November 24, 1942, and in the copending application of Flynn and Kramer, Serial No. 478,644, filed March 10, 1943; and has among its objects improvements in plotting instruments, particularly relative to improving the means for carrying the tracing point in such manner that maps can be reproduced on an enlarged or a reduced scale, and such other objects as will be apparent from the following description and claims and the annexed drawings, in which:

Figure 1 is a front elevation of the plotting instrument;

Figure 2 is a section on the line 2-2 of Figure 3;

Figure 3 is a side elevation of the instrument;

Figure 4 is a fragmentary section on the line 4-4 of Figure 1; and

Figure 5 is a section on the line 5-5 of Figure 2.

Referring to the drawings with more particularity, the embodiment illustrated is provided with a base suitably supported on adjustable leveling rests l2. Frame members l3 and I4, shaped to provide uprights l5 and I6 and horizontal arms I! and I8, respectively, are suitably secured to the rear of the base with the horizontal arms extendfront and rear bars l9 and extend across the forward ends of the horizontal arms and are secured thereto by set screws 2| in the manner illustrated.

A unit 22, forming part of a stereoscope and having eye pieces 23 and Z4 and eye mirrors 25 and 26, is carried by bracket 21 which, in turn, is carried on another bracket 28. The latter bracket is adiustably mounted on the front bar I!) with a tight sliding fit, and has a rearwardly extending projection 29 positioned beneath the rear bar 20. A wing screw 33, threaded through the projection 29 and engaging the bar 20, provides for adjusting the position of the unit 22 vertically. The unit 22 is adjustable on horizontal pivot bolt 3| by manipulation of screws 32 and 33, which are threaded through projections on bracket 21 and bear on an abutment 34 fixed to the stereoscope unit 22, and is adjustable on vertical pivot bolt 35 by manipulation of similar Transverse parallel screws, one of which is shown at 35, which are threaded through other projections on bracket 21 and bear on a stationary abutment 31 fixed to the bracket 28.

Stereoscope wing mirrors 38 and 39 are carried by brackets 49 and 4|, which are also slidably mounted on bars l9 and 20 and are made adjustable by means similar to the means for adjusting the unit 22.

Phototables 42 and 43 for supporting the stereoscopic pictures are suitably mounted on the front of the base H. The manner of supporting and adjusting the tables is substantially the same as that described in the above-mentioned patent, to which reference is made for a complete description thereof Frames 5| and 52, carrying index mark disks with the index marks movable in three coordinate directions in the field of vision of the stereoscope, are mounted on horizontal bar 53, which in turn is mounted for vertical movement on racked vertical columns in the form of tubes 54 and 55, and is operated by a hand wheel 56 driving a shaft 51 to which pinions, one of which is shown at 58,

1 are attached and meshed with the racked tubes.

A graduated scale wheel 59 is movable with the hand wheel, and its setting is indicated by index pointer 30.

The bar 53 and parts carried with it are counter-balanced by weights one of which is shown at 6| disposed inside the vertical tubes 54 and 55, re-

spectively. The counterweights are suitably connected to the bar by flexible cables 62 and 63, which are attached at their free ends to the counter-balanced parts, and are belted over pulleys 64 and 65 attached at the top of the tubes to hinge knuckles 89 and 90.

Frames 5| and 52 are made adjustable relative to each other. Frame 5|, for example, is adjustable vertically and horizontally by manipulation of screws 66 and 5! the first of which is journaled in a bracket 68, which is slidable on bar 53, and is threaded through the frame. Screw E1 is journaled in a bracket 69, which is fixed on bar 53, and is threaded through bracket 55. The frame 5| is guided in its vertical movement by guides 10 secured to bracket 63 and slidably fitted in apertures extending through the frame.

A horizontal rod H is attached at its ends to the lower ends of tubes 54 and 55.

The parts heretofore described, although improved in structure, are substantially the same in their general function as the corresponding parts The means for movably supporting the parts carrying the index marks 1s, however, different from the corresponding means of the patent. This means, as shown most clearly in Figure 2, comprises a linkage of rigid members, or sides, formingat least two parallelograms with a common side, with the side of the first parallelogram opposite the common side fixed against movement, and with all corners hinged, allowing freedom of movement in all horizontal directions of the unfixed side of the second parallelogram which is opposite the common side and which forms a carriage for the index marks,

The first parallelogram has as its fixed side the base H to which the uprights l5 and it are fixedly secured. Sides Bil and 8%, which are of equal length, are hinged at their ends to the uprights 0n pintle pins 82 and 83, respectively, and at their opposite ends to the ends of the common side 8-5, which is of length equal to the distance between the hinges on the uprights, on pintle pins 85 and 8G. The second parallelogram has its sides 87 and 88, which are of equal length, hinged at their ends on pintle pins 85 and 86, and at their opposite ends on the movable side, or carriage, which is also of length equal to the distance between the hinges on the uprights and which comprises horizontal bar 53, rod H and tubes E4 and The tubes are journaled at their ends in hinge knuckles 89, 99, Si and 92, integrally attached to the ends of the sides Bl and 88. For ease in movement, the pintle pins may be fixed in reference to'one of the sides and frictionless bearings (not shown) provided at the bearing points.

From the structure disclosed, it will be observed 2-" that the index marks are carried by the movable side of the linkage and will always remain in the same position relative to each other, except for adjustments and vertical displacements; and that the linkage is supported solely by th frame and .the index marks are constrained to move in traversing the stereoscopic pictures so that every position of the marks is parallel to every other position.

The parallelism linkage above described is essentially the same as that described and claimed in the copending application f Flynn and Kramer, mentioned above.

The improvement in this application over the copending application relates to the means for carrying a tracing point which provides for drawing maps on enlarged or reduced scales, the principles of which means are most clearly illustrated in Figure 2.

The means for making enlarged maps comprises an enlarging linkage system, shown at the left of Figure 2, attached to the parallelism linkage and carrying the tracing point. The linkage system is provided by a link Hi0 fixed to the side 86 and equal to it in length. In the particular embodiment shown, link is formed as an integral extension of lower member llll of the side BE. A link 32, twice as long as link I00, is attached at its one end to the free end of link llitwith a hinge joint, and carries the tracing point I63 at its. other end. Link 34, of length equal to link M59, is attached at one of its ends to The tracing point will traverse a figure similar and of double scale to any figure traversed by the index marks.

If it is desired to reproduce a figure on reduced scale the reducing linkage system shown at the right of Figure 2 may be employed. The two systems may, if desired, be used concurrently for the purpose of simultaneously making more than one map.

The reducing linkage system is provided by a pair of links Fill and H38 connected together at their ends with a hinge joint and arranged to be adjustably connected with hinge joints at their other ends to sides 8| and 83, respectively, of the parallelism linkage. The adjustability, which provides means for varying the scale of reduction, is provided by a series of apertures I09 and III] in the lower members HI and H2 of the sides SI and 88, respectively, and another series of apertures in links It! and N38 to be selectively mated with the first-mentioned series of apertures and held in position by bolts H3 and Wing nuts I M and I I5, in the manner illustrated. The series of apertures are so positioned that the links I01 and H18 and members Ill and H2 form a parallelogram, for different reduced scale adjustments. A tracing point H5, similar to tracing point m3, is carried at the hinge point of links it]? and its, and a map table I I! is supported on base H beneath the tracing point H6. Smaller scale figures are produced when the adjustment of links Hill and I 08 provides the smaller parallelogram.

From the above, it will be understood that this invention combines a parallelism linkage with a pantograph, the parallelism linkage being disposed between the usual fixed point (82 in the case of the enlarging pantograph and 83 in the case of the reducing pantograph) and scanning point (39 in case of the enlarging pantograph and iii) in case of the reducing pantographl of the pantograph. The enlarging pantograph, as shown in the drawings. has an extended link and another link, connecting its fixedand scanning points, in common with sides 8!! and 87, respectively, whereby its fixed and scanning points coincide with hinge joints of the fixed and movable sides of the parallelism linkage atone end. Similarly, the reducing pantograph has links connecting its fixed and scanning points in common with sides 8! and 33, whereby its fixed and scanning points coincide with the hinge joints of the fixed and movable sides of the parallelism linkage at the other end.

It is to be understood that additional pantographs may be combined in series with either the enlarging or reducing pantograph to obtain .difierent scales of enlargement and reduction without departing from the spirit of this invention, such combinations being well known in the art.

Having thus described my invention, I claim:

1. A plotting instrument comprising a parallelism linkage provided by rigid members forming two parallelograms having a common side and having all sides connected at the corners of the parallelograms with hinge joints, the side of one parallelogram opposite the common side being fixed against movement, he corresponding side of the other parallelogram being movable; in combination with an enlarging pantograph and a reducing pantograph, each pantograph having a fixed point, a scanning point, and a tracing point, the fixed points of the pantographs being coincident with the two hinge joints of the fixed sides of the parallelism linkage, respectively, and the scanning points being rigidly connected to the movable side.

2. In a plotting instrument of the character described, a frame, a stereoscope supported by the frame and index marks movable in the field of vision of the stereoscope, said index marks being carried by a parallelism linkage provided by rigid members forming two parallelograms having a common side and having all sides connected at the corners of the parallelograms with hinge joints, the side of one parallelogram opposite the common Side being fixed against movement relative to the frame, the corresponding side of the other parallelogram being movable, the index marks being carried by the movable side, whereby they are constrained to move in traversing a stereoscopic picture so that every position of the marks is parallel to every other position; in combination with an enlarging pantograph and a reducing pantograph, each pantograph having a fixed point, a scanning point, and a tracing point, the fixed points of the pantographs being coincident with the two hinge joints of the fixed side of the parallelism linkage, respectively, and the scanning points being rigidly connected to the movable side, whereby for any figure traversed by the index marks the tracing points of the pantographs will traverse similar enlarged and reduced figures.

3. A plotting instrument comprising a parallelism linkage provided by rigid members forming two parallelograms having a common side and having all sides connected at the corners of the parallelograms with hinge joints, the side of the parallelogram opposite the common side being fixed against movement, the corresponding side of the other parallelogram being movable; in combination with an enlarging pantograph having an extended link in common with the side of one ofthe parallelograms adjacent the fixed side, whereby the fixed point of the pantograph coincides with the hinge joint at the end of the fixed side, a link in common with the side of the other parallelogram adjacent the movable side, whereby the scanning point of the pantograph coincides with the hinge joint of the movable side, a link rigidly connected to the extended link, a link hinged at one end to the end of the rigidly connected link and carrying a tracing point at its other end, and a link connecting the scanning point of the pantograph to the central portion of the link carrying the tracing point.

4. A plotting instrument comprising a parallelism linkage provided by rigid members forming two parallelograms having a common side and having all sides connected at the corners of the parallelo-grams with hinge joints, the side of the parallelogram opposite the common side being fixed against movement, the corresponding side of the other parallelogram being movable; in combination with a reducing pantograph having two links in common with the two sides of the parallelism linkage adjacent the common side, whereby the fixed and scanning points of the pantograph coincide with the hinge joints at the end of the fixed side and of the movable side, respectively, and two links connected together with a hinge joint and carrying a tracing point coincident with the hinge joint, said lastmentioned two links being adjustably connected with hinge joints to the first-mentioned two links, whereby for any figure traversed by the scanning point, the tracing point may be made to traverse a similar figure of a reduced variable scale.

ALBERT J. KRAMER. 

